Gear-cutting machine



F. w. JURY GEAR CUTTINGMACHINE Sept. 11, 1928. 1,684,099

, 6 Sheets-Sheet 4 f2 Ma/'Ury www F. W. JURY GEAR CUTTING MACHINE Filedl June l, 1926 Sept. ll, 1928.

' Sept. l1, 19.28.

F. w. JURY GEAR CUTTING MACHINE Filed June l, 1926 6 Sheets-Sheet 5 Y FME/mfg Sept. 11,1928.

.F.w. JURY GEAR CUTTING uAcnINE 6 Sheets-Sheat 6 Filed June l. 1926 Patented Sept. 11, 1928.

UNITED STATES P AIENT oei-"ic Y FRANK W. JURY, on MILWAUKEE, WISCONSIN, Ass'IGNOR To '2HE FALK CORPORATION,

OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

GEAR-CUTTING MACHINE.. l

Application filed June 1,

Thisr invention relates to gear cuttingmachines. y

Objects of this invention are toprovide a gear cutting machine adapted to cut double helical gears.

Further objects ot this invent-ion are to ment over that disclosed in my nrior Patent ii/:1,456,240 of hlayQQ, 1923, for gear cut-v ting machines, and has the .sa-nie general'objects as those disclosed in such patent.

Further objects are to provide a. novel form ot `gear cutting machine in. which the` slides :torcarrying the cutters are independently operated by a pair of independent cranks, which are connected in `a positive manner, and to 4provide" a novel tormof ad-y vancing means which is so constructed that the major portion of it runs continuously in a uniform manner without starting and stopping, and iii whichmeans are provided for combining the advancing or indexing motion of the work with the normal advance' ot' the cutter so'that the work and the cutters move in the proper'relative manner to secure a proper development of the'teetli.

Further objects are to provide a gearcutting machine in which a high speed maybe obtained, in which no over running ot theY feeding mechanism can occur; 'in which' there uo back lash, and in which the an,- gi'les oi the teeth, of the cutters, and of the cutter guides are uniform throughout.v

Further objectsare to provide a gear. cutig vinaffliine in which the work is stationiy while the cutting takes place, iii which i. ii

the construction is such that a very rugged and simple machine results, and which is practical to operate tor the production ot small or large gears' in an economical manner. Y .v f

In general. the machine consistsof two independent cranks which are continuously driven from a. source of power andvindepcndeiitlyroperate the cutters, such cut-ters being-set approximately 90 apart and guid- 192'6. sriai No. 112,979.'

ed in independent angular guides. These cutters operate upon work which is driven or indexed in a step by step manner, andin which additional movement is given tothe work to correspond to the gradual upward. feed ot' the cutter guides.

vAn embodiment of the invention is shown inthe accompanying drawings in which Figure l is anen'd View of the gear cut-V ting machine showing in imaginary lines the outline of they blank or work;

Figure Qfis a. front View of the machine;

Figuref is a plan view of the machine with the Acutter head in section.

F ignie L is a gearing;

Figure 5 lis a rdetail of thedifl'e'rential forming a portion of thegearin'g;

Figure 6 isl Aa detail of a portion of the gearing showing the Geneva wheel g Y v Figure 7 lis a detail in section vshowing the cone chang)l gears and associated parts;

Fi (Tures 8, 9, l0, 1l are diagrammatic face views showing the'position of l.the cutter vblocks at successive stages in the cycle ofy operation. Y

Figures 81,792 l0;L and' ll2L are corresponding views showing the position ofthe cut- .teis at the instants corresponding to those indicated iirFiguresS to ll inclusive;

diagrammatic view of the that the machine comprises a` bedl which carries a main head 2 and an auxiliary head or tail stock 3as most clearly brought out in FigureV 2. `These members are moved ,along guides formed in the bedl in'any suitable'man'ner, as bvme-ans of the hand wheels A; and 5-for drivingy thev screw threaded shafts, as indicated' at'the rightfhand side VOt Figure 2, so as to advance theheads or! retract them for the proper positioningvo theA mandrel which carries the 1 work oi" blank. Thebedalso carriesacutter head, indicated generally by thef reference, charafter 6, and shown most Clearly'in Figures 1, 2, and 3. This cutter heed is'alsomount ed on guides at right angles to those previously mentioned and is advanced or retracted by means of the hand wheel or in any other suitable manner. In addition to these main portions the bed carries a fourth main unit, namely, the gearbox 8 which is preferably mounted to the side of the bed, as indicated particularly in Figures 1,2, and

The worker blank W rotates in the direction indicated by the arrowsin Figure l,v and the cutters, in addition to their reciprocatory motion, travel upwardly, as 1ndieated by the arrow in Figure 1.

'lt'hev general Inode of operation of the niachine is follows:

rl`he work or blank is rotated in a step by step manner, and the cutters reciprocate in and out on slanting lines corresponding to the angles of the double helical teeth; The work is held stationary during each stroke of the cutters and each cutter comes to th center line and is withdrawn from the work'.

and travels baclrto its initial position. The

' cutters are operated by cranks ,set approximately 9()O apart, and are hojth simultaneously out of the work for appro-imf-rtely one-quarter of a revolution of the cranks. During this period the work indexed and vthe cutters execute cuts thereafter Vduring the next cycle forming the next teeth.

vThese teeth are not formed completely on any portion ef the work, but' are partially formed complete around the blank, and as the cutters are tapered and Aare fed upwardly, the depth of cutA and, consequently, the shaping of the tooth progresses steadily until the entire tooth outline is formed coin-- plete around the work.v ity is to be noted that the indexingl of the blank insures the correct generation of the tooth `outline Yas the critters are also moved slowly upwardly. lVhen the critters 4have traveled through their complete upward stroke, the teeth are complete entirely around `the blank.l ln this way the proper generation of teeth is se-A curedy and also unequalled expansion or change in the internal structure of the blank is avoided for the initi al or inherent stresses in the blank are' not relieved at any one point, but are gradually relieved by thel small cuts completely around the entire blank. Consequently, the finished gear is absolutely true with reference to its axis. lyhaving the work rotate in one direction in a step 'by step manner and by having the cutters travel in the opposite direction, it is 'clear thatback lashing of the gear train is always taken up and, consequently, no error rcan occur in the finished gear.

lt is, ofcourse, to be understood that the direction'of rotation and also the direction of Vtravelof lthe .cutters may be reversed ywithout departing from this invention.

rlhe' entire machine is normally driven from a main motor 9 carried in the cutter head 6, as shown in Figure 3, and motion is transmitted from the mechanism inl this head to the gear train in the gear box 8',v and from thence to the main or drive head 2. However, it is sometimes desirable to uickl i rotate the work or to uickl f move the cutters. This is accomplished by means of an auxiliary Ymotor 10 which normally is not in operation, but which may be through the, medium of shift gears, hereinafter described, thrown into operation to perform the two functions mentioned above.

lith this brief outline of the general operation ofthe machine, the details of construction will be given.

The cut-ter head and associated mechanism will first be described.

Referring to Figure 3, it will be seen that the main motor shaft 11 carries a worm 12 which meshes with a worm wheel 13, rigidly carried by a transversel jack shaft 11i. This construction is also diagrammatically indicated in Figure et. This transverse jackV shaft carries a pair of worms 15 at opposite ends. These worms drive wheels 16 and 1'? carried by cranlr shafts 19 and 18, and r0- tate the crank shafts in the'same direction. These crank shafts, as will be seen from 'Figure 8, are journaled in thev front and reariportions of the cutter head 6 and are provided with discs equipped. with crank pins 2O and 21. One of the cranl-z shafts, 19 for instance, is provided with a bevel gear 22 which meshes with a bevel gear 23 carried by a diagonally kand outwardly extending shaft 24, as maybe seen. from Figures 8' and 4l. The lowerl end of this slanting shaft 2li carries a bevel gear 25 which meshes with.

a bevel gear 26 slidably splined to a forwardlyextendmg shaft 27j This forwardly extending shaft transmits motion to they train of gears in the gear box 8 by means hereinafter describe-d. the gears 25 and 26 andthe corresponding portions of their shafts are mounted withinV lt is to be noted that llo a brac-liet 2S rigidly boltd rto vthe cutter head 6 so that this bracket movesA forwardly or rearwardly with the cutter head. t. The cutter head 6 carries a sliding front plate 29 (see Figures 1, 2, 3, and 12). rlhis sliding plate is carried by suitable guides or ways formed on the cutter head, as shown in Figure 3, and these lgrides and ways are formed adjacent the ends of the sliding plate. ln addition to theseguides central guides are provided for carrying the central dove tailed inwardly projecting rib 30..

VThis rib most clearly vshown in Figure 3. The rib is apertured and internally threaded and receives the vertical feed screw 3l bv means of which the 'sliding plate 29 israised or lowered.

This feed screw'is carried in upper and. vlower bearings, and is provided with a worm wheel 32' rigidthereoinsee Figure 4. This wornrwheel is.` driven byfineansf of a worm 33 rigidly carried by ar transverse shaft 34. The outer eiidoff'the shaft 34 is connected by means-ofsgears 35 and-36.to aT short shaft 37, which projectsoutwardlythrough the cutter head` G. This shaft 37,

as most clearly shown in F igurev 4,'.carriesA a worm wheel 38 at its `outer end. This worn'i'wheel 38, as ymay be seen from Figures a l and 4, meshes with afworm carried bymeans of a bracket 40 bolted to the cuttery head. The worm 39 is slidablyl splined to the forwardly eXtendinG shaft 40, so that when such shaft is driven by ineans'herein-V per guides 4l anda pair of lowerguides 42.y Between these Ouides a. Jair? of slides 43 are positioned.- These slides travel in the angular'inanner caused b the (ruidos-and, con--V VJsequently, define the angular teeth off' the bla-nk through the medium of cutters carried thereby. Iii-reality, the cutters 44 and 45 are carried by: cutter heads-46 which are fastened to the'slides 43.# The cutters 44` Aand Ll5-'have cutting` teeth, :as indicated in F ig'ures'l, 2, and 3, and Ahavt-iabody portion whichis pivota-lly' mounted upon the cutter heads 46. The' cutter heads are provided with stops 47 against which thc cutters contact when swungbackwardly by mechanism hereinafter described. Theyv are stopped in the'othcr direction by their bases contacting with the cutter heads 46.'y

The slides or cutter heads 465` are rigidly secured to slides or blocks 48' which are guided in angularly arranged "slots .49' formed`in the vertical plate 29, vas indicated in Figures 2 and 3. These guides o'r blocks'48 carry crank' pinguides? 50 'which extend transversely across the blocks or slides 48,

'indicated in'Figure 3. These crank pin' guides 50 each have a vertical slot formed therein for the reception of the respectivecrank pins 2O and 2l. y

The purpose of this construction `is to transmit reciprocatory motion to the cutters from-the cranks, and it is to be particularlyv noted that although the plate 29 may move upwardly or downwardly that nevertheless the same reciprocatory inotionisl imparted to the critters. irrespective of the position ot trie vertically slidable plate 29.

Itfwill be seen from-.the inechanismthus fai" described, that provision 'is made for reciprocating the cutters with definitely related timing, andat the-same time for raising and lowering the ,cutter carrying plate 29,' without -interferriiig with the reciprocatory motion' of' `theco'rrect timing the'cuttinof. l

iinishing its kidle stroke.

Inforder to draw the cutters out of the cutters abouttheir-pivot points with respectto their cutter heads. This meansiifs identically the saine for each cutter and only one need, therefore, be described. Consider, for example, one of the cutters. The cutter is provided with a ball soc-ketf51 which receives' the ball at the inner end of the link 52, such link extending upwardly in a slanting manner,` as indicated inV Figures '2 and 3.l The outer endof the link isialso provided with a ballwhichis received byv al ball socket` 53. This last ballw socket 53 is carried by a split-friction*block 54, asshown in` Figures 13. The friction block consists of two inembers wliichjare provided withA in-ternal recesses, which in turn receive expansion Y s )'riiio's -55- such s Jrinfrs tendinO to uroe theb 3 C D t? parts ofthe` friction lblock apartV The two members of the friction block are guided by. means Vof pins F rom Figure 13 it will be noted that the upper guide 4l is in realil `ity'an auxiliary guide and overliangs andA enfcloses the friction block 54. Thus they friction block has a frictiondragv due to the spring pressure, land tends to vlag' behind the,

motion of? the cutter. Consequently, during IUU block vrocks Vthel links 52 inthe 'opposite dii ifection and, consequently, rocks the cutter intothe position shown forr the right hand cutterof F iO'ure 3 and thus retracts the cutter:andwith'draws it from the work.

Thus it will be seen thatthe cutters swing or move outwardly finto working position prior toengagement with the work and eX- ccute their working stroke on the .return stroke.v The cutters are swung inwardly orl withdrawn from the work ai'idexecute their idle stroke. v f

vThe cycle of operation-ofthe cutters is indicated -in 'Figures 3 to l1 and 3 to 1l. In Figure and Figure 8, it will be seen that the cutter 44 is" on'its idlestroke and is retracted from the work while the cutter 45 is just finishing its working vstroke and is 'in the work. In 'Figures 9 and 9a bothcutters are executing their idlevstroke and are retractedvfrom the' work.v In Figures lO'and l0a the cutter 44 is just beginning its working stroke and the cutter 45 is just At the instant when both cutters arev clear of the work which would correspond to a position between the positions indicated in Figure 9 and Figure l0. The work isindeXed-or scribed. lFigures l1 and 1la show the cutter 44 just finishing its working stroke and the cutter 45 just beginning its working stroke.

It will .be seen, therefore, that the strokes v"of the cutters are so timed that they are out of each others way, and also are clear of the work for approximately a quarter revolution of the crank shafts.

It is', of course to be understood that the length of stroke of the cranks is suoli as to afford ample clearance of the cutters' with respect to the work and, obviously, any of the well-known means may be employed for adjusting the cranlrs, if desired.

It is to be noted from referenceto Figure l that the cutters feed upwardly, while the work rotates in the direction indicated by the arrow. Further, it will be seen from this ligure that the cutters ai'e tapered and their teeth increase in length towards the lower end of the cutters.

The angle of the cutter teeth, and the angle of the guides 4l and 42 for the cutters, is' identical with the angle of the teeth in the finishedv gear. Further, it will be noted from the mechanism hereinafter described, that the work is held stationary during the cutting operation and, as previously vdescribed, is indexed during the time that the cutters arev both out of the werk.

The means foi' transmitting motion to the work will 'now be described. The driving shaft 27 which is driven from one ofthe crankshafts, as previously described, is provided with al gear 57 at its forward end, and this gear meshes with a gear 58 carried by a longitudinally extending shaft 59. The shaft 59, therefore rotates continuously and extends into the gear box 8, as. inost clearly shown in Figures 3 and 4. The shaft carries one portion of the Geneva wheel, as shown in Figures 4 and 6, and

'f such portion consists of a disc 60 provided with' a central'hub 6l kcut out upon the arc of circle, as indicated at 62. The dise also carries a pin 63 which moves into the slots 64 of a star wheel 65, such star wheel being provided with cut outs formed on the arcs of circles, and indicated at 66. The star wheel is mounted upon the short jaclr shaft 67 and, consequently, a quarter turn Vis given to this shaft for each revolution of the shaft 59.l

Further, this motion is very quick and takes place through a small fraction of a turn of the vshaft 59. However, due to the interlocking engagement ofthe hub v6l and the cut out 66. as indicated in Figure 6, it is apparent that no over-running can occur, and the shaft 67 accordingly positively turned a quarter turn and their held locked in position.

The shaft 67 extends to the differential 68 and is rigidly secured to the bevel 'gear 69. The differential consists of the body,

portion which carries the worm wheel 70,

such as indicated at 74', the change gearsl being located on the outer side ofthe gear box 8. Thel gear 74 meshes with an idler.

gear 75 which, in turn, meshes with a gear 76, such latter gearbeing mounted in a. manner hereinafter described on a shaft 77 which projects completely through the gear iox S, as shown mostclearly in Figure 4.

The shaft 77 is splined and slidably carries the driving pinion 7 8 which meshes with the gear 79, carried by the work driving shaft 80. This work driving shaft 8O is mounted within the main head 2 and carriesl a center pointv 8l and a face plate 82by means of which the work may be centered and rigidly attached to the driving shaft 80.

It is, of couise, to be understood that the tail stoclr 3 is 'provided with a center-point 83 and with the usual hand wheel 84 for advancing or retracting this'eenter point.`

Means are provided for feeding the plate 29 upwardly by meansA of the screw 3l.

This means has been previously partially described and the description thereof will now be completed. The shaft 77 carries a gear 85 which normally meshes with 'a gear- 86 slidably splined to atransverse shaft 87 carried within the gear box 8, as is apparent from Figure 4. Thus the shaft'87 is driven from the shaft 77 in the normal operation of the machine. This shaftl 87. carries a series of cone gears 88.which may be selectively coupled thereto. .These cone gears mesh with cone gears 89 rigidly mounted upon a. transverseshaft 90. The shaft 9() progects through the gear box 8 and carries va gear 91 whichmeshes with a gear 92 'cari'ied by thelongitudinally extendingk shaft 93.` 4The shaft 93 is coupledvto the shaft 4() by means of the bevel gears 94 and 95, as most clearly brought out in Figure 3.- From this point the mechanism has been descr'bed and it will be seen that asthe'shaft 93 is rotated, feeding motion is vtransmitted to the plate 29.

The shaft 90 is provided with va bevel gear 96 which meshes with a bevel gear 97` carried by the shaft ofthe worni98, as

shown in 'Figure 4.' Theworm 96 meshesv with the worm wheel 70 of the dierential, Y

and thus its motion is compounded withthat furnished withtheshaft 67, previously described.

In this connection it is'to be noted .thatthe amount of feed of the plate .29.with` reference to the rotation of the shaft- 77 and,

llo

llh

consequently, with reference to the lshaft 80 is controlled by` means of the change gears r91 and 92, which are mounted on the outer side of the gear box 8. The gears 91 and 92 `thus control the ,pitch or spacing of the teeth cut in the blank,iwhile the gearsf74, 75 and 76, also mounted on the outer side of the geai box 8, determiner the number of teeth which are tobe cut in the blank.

By-means of the differential, the shifting `motion of the cutters in their upward travel is compensated or combined with the motion normally imparted to the work, so that the Vwork and the cutters willat all times be in exact register. v

It is to be Vparticularly noted that the "screw Y31- is permanentlyftied to the shaft A9 0 after the selection of the gears 91 and L92 has been-made, so that any motion of the by means of the selective cone gears which mesh with the 'fixed gears 89, The construction of these `gear-sis more clearly shown in Figure 7 which is a sectional view through these gears, and which diagrammatically shows-other ofthe related gears. -Each of theL gears 88 is carried by bear-ing rings 99 rigidly'k mounted yupon the shaft l87. The gears 88 are eachy provided with Ya key slot, as indicated at 100 in F igure'7,

and-a spring pressed key 101is adapted to snap into any -one of the key slots. This spring-pressed key 101 'is carried by va rod 102 slidablyvmounted vwithin the shaft 87, and such rediris-provided with a transverse slot for the reception of theA key 101 and the spring and vmechanism associated therewith.

'It is to be noted that each'of the rings 99 is beveled Aon its inner-face, and that-the edges of the key 101 are similarly beveled.

Thus, as the rod 102 is moved with reference Ato the shaft 87,the key willY be depressed by the rings 99 and detachedfrom thev gears Y 88. Howeveiywhen the keyfrides from beneath the rings 99, it will again snap into ythe selected key slot 100.

AnyY suitable means may be 'provided for shiftingthe rod 102. vFor example the rod may be provided with'a plurality ofhannuf llai' ribs 103at itsprojecting end which mesh .with the-teeth of a spur geai104vcarried within Va suit-able housing A105, and operated by a manipulating crank 106. 4It is tov'be noted that the rod 102 rotates with the` shaft 87 as the` key 101 passesthrough a lslot in the Vshaft 87,:and necessarily .rotates the rod with such shaft. y

It issometimes desirable to quickly drive the screw 31 and, consequently, quickly raise the vertical slide plate V29 with the cutters.

This is readily accomplished by providing the auxiliary motor 10 and connectingY its sprocket wheel 107 to the sprocket wheel 108 of an auxiliary or jack shaft 109, as shown in Figures 3 and 4f. This jack shaft carries a pairof stationary gears 110`and 111. 'Non mally, these gears are out of mesh.v with other gears in the gear rbox`8. The gear 86, previously described, carried bythe shaft 87 is slidably splined to such shaft and is adapted `to be moved out of engagement with itsdriving gear. 85, and to be placed in engagement with the gear 110. This connects the auxiliary inotoi operatively with the elevating screw 31 and,rconsequently, permits the rapid elevation or lowering of thecutters. However, the cutters and work do not get out of step, as' the shaft 90,which'formsV a portion of the motionl transmitting mechanism of the screw, is permanently coupled'with the shaft 80. through thevdifferential,and through the gear train' on the outer side of thefgcar box. Consequently, the work and cutters are at all times maintained in correct relative position.

4It is also sometimes desirable to quickly rotate the work. rThis is also easily accomplished by providing a sliding gear 112 splined'to the shaft'77, asfsliown in-Figure f1.

they auxiliary motor may quickly rotate the work. V"The gears 86 and 112.*are operated by forked'levers indicated in Figure 4 and spectively sin' Figure 1.

The operationofthe `apparatus is as follows:

.This slidingl gear maybe moved intoengageement. with the. pinion 111- and," consequently,

-these leveisextend outwardly through the .gear box 8, as indicated at 113 and 114 re- Themotor `9 drives the crank shafts 18 and y19 and reciprocates the cutters. Motion is transmitted from `these shafts to Athe shaft .'59 which entersfthe gear box and drives the disc 60 of the Geneva wheel. This transmits intermittent motion to the shaft 67-which op- Y erates through the differential 68 and operates the gear trainsi74, 75, and 76 on the side vof the gear box. y From this point, motion of the' shaft 78 .is transmitted to the driving .shaft A80 for the Work.k The screw31 is driven Vfrom the gear 85, (see Figure el) `whichtransmitsmotion to the gearl 86 and rotates the Shaft 87. This shaft-is coupled to the shaft 90 by means of the selectivercone gears 88 and 89, (see Figures 4 and`7) and, consequently, drives the shafty 90 at the se lected speed. Thisshaft190 is coupled to the .shaft-.93 by means of the ,gears 91 and 92 on the outer side ofthe gear `box,as shown in Y Figure 4. The shaft 93 through the gear train, previously described, drives the screw 31 and, consequently, elevates the cutters While they continuously reciprocate. The motion of the screw 31 is compounded With that 4of the Work through the medium of the ditterential 68, which is operatively coupled not only to the shaft 67, but also the shaft 90, as is apparenty from Figure 4.

It is to beunderstood that the change gearV v from the outer side of the gear box and, con- Y sired number j construction of the machine which permits sequently, it is a simple mattei' to select the appropriate combination of gears for the deoi teeth and also for the pitch. It Will be seen that the work is fed, as indicated in Figure 1, and the cutters ted up- Wardly, as indicated insuch ligure. Consequently, there is no back lash and no lost inction which would interfere with the accuracy of the Work. Further, it is to be noted that While the Work WV rotates a number ot times the cutters travel upwardly their full lengthcand when they have traveled their full length upwardly, all of the teeth are completely finished around the Work.

It is to be noted further that the sliding gear 86 may be moved out of. mesh with either the gear or the gear 110 and, consequently, can occupy a neutral or intermediate position. Under these conditions, it is possible to rapidly rotate the Work independently of the 'feeding of the cutters.

This rapid rotation of the Work is accom-A plished by moving the gear 112 into engagement with the gear 111. When this is done, the clutch 115 is open and, consequently, the

' gear 76 is disconnected from the Vsha-tt 77.

This rapid rotation ot the Work is frequently desirable for trimming up the gear, after it has been completely termed and Without taking it from the mandrel.

This machine can be expediently used not only yfor the formation ot' large double helical gears, but may also be eiiiciently used for the formation oi small gears, which necessarily must be sold rather cheaply.

.The above results are possible due to the its rapid operation and thus secures a very economical mode of operation with a minimum los's of time,

.It is to be noted further that the machine, although accomplishing the results enumerated above and forming double helical gears of the utmost accuracy, is nevertheless relatively simple and extremely sturdy in construction.

crank shafts having cranks thereon, meansl for rotating said shafts, a pair of angularly set guides, a pair oit' cutter carrying meinbers directly operated from said cranks, cutters carried by said members, meansfor supporting and rotating a blank adjacent said cutter, gearing transmitting motion to said blank rotating means, andl intermittent motion mechanism interposed betiveen said gearing and saidblank rotating` means for intermittently rotating said blank in one direction only, whereby said blank-is rotated in a step by step manner as saidcutters oscillate and rotates in the saine direction throughout the entire operation of the inachine in producing a complete gear, said cutters executing only a single cut on each successive tooth completely around the blank until the entire gear is formed.

2. A double helical gear cutting machine,- .comprising a cutter head having a pair of crank shafts arranged therein, a pair ot guides carried on the front or' said cutter head, cutter carrying members guided Within said guide, cutters carried by said mem-` bers, said cutter carrying members having vertically slotted projecting portions .Clirectly enga-ged by said cranks for transmitting motion to said cutter carrying members while permitting feeding motion of said cutters transversely to saidfcranks, means for feeding said cutters 'transversely to said cranks, and means for holding and rotating Work adjacent said cutters.

3. In a machine for cutting double helical gears, the combinationof a cutter head having a pair of divergent guides, a pair o1' cutter carrying members guided by said guides, cutters carried thereby, means for moving said cutters in'and out asV said cutter carrying members are reciprocated, independ-.

ent means for reciprocating said cutter carrying members, means for holding work and rotating such Work adjacent said cutters, a gear train operatively connectingvsaid `cutters to each other and to said Work holding- 120 means, intermittent motion locking.. mechanism interposed insaid gear train for causing a stepy by step indexing of saidfwork holding means, means for feeding said cutters` transversely paths, and means for combining the feeding motion of said cutters iviththe' 'motion4 imparted to said Work holding means, Y A Il.' A machine for cutting` gears, comprising a cutter head, a slidable plate carried to theirA ieciprocatory;

Aby said cutter head and having angular guides thereon, a cutter carrying member guided by said guides, a crank operatively connected With said cutter carrying vmember, means for moving said slidable plate With reference to said cutter-head,` Work holding means for holding andindexing the Work adjacent said cutter, a gear train connecting said crank and said Work holding means, lmeans for combining the motion of said plate with the motion transmitted to said Work holding means, a. main drive for driving said crank and Work holding means and said plate, and an auxiliary drive for selectively driving either said Work holding means or said plate.

5. A gear cutting machine, comprising a cutter adapted to reciprocate, means for driving said cutter, means for feeding said cutter transversely of the direction of reciprocation, a main drive for the cutter reciprocating means, means for holding and indexing the Work adjacent said cutter and connected with said main drive by means of gearing, mechanism combining the motion transmitted to said Work holding means with the feeding motion of said cutters, and an auxiliary drive adapted for connection with said gearing and adapted to simultaneously shift the cutters transversely of their direction of reciprocation, and for corre` spondingly moving the Work to insure correct registry of the cutters and said Work.

G, A gear cutting machine adapted to cut double helical gears comprising a pair of crank shafts, a pair of cutters guided in angularly set guides and operated from said crank shafts, said crank shafts being set approximately 90 advancing the guides, a Work carrying spindle, means operatively connected to said crank shaft for advancing said spindle in a step by step manner when the cuttersare out of the Work to index the work, and means for modifying the indexing of t-he Work' in accordance With the advance ofthe cutter guides. y

7. A machine for cuttingdouble helical gears comprising a pair of independent angularly guided cutters, means for reciprocating said cutters independently of each other, a Work carrying member, means for advancing said Work carrying member in a step by step manner When the cutters are out of the Work, means for gradually advancing the cutter guides, and means. for combining the advancing motion of the cutter guides With the indexing motion ofthe Work whereby the proper relation of Work and cutters is maintainedV at all times to secure proper generation of the teeth.

8. In a gear cutting machinethe combination of a cutter head having a slidably mounted plate provided With guides, a cutter carrier mounted Within said guides, a

apart, a feeding means for rcutter carriedgby said cutter carrier, means carried lWithin said head for imparting re- .ciprocatory motion to said critter' carrier, Work carrying-members, one of said members being' adapted to drive said Work and index such work, a gear train operatively coupling said cutter reciprocating member and said Work indexing means, said gear train having a train of interchangeable gears for determining the number of teeth to be cut on the Work and having a second set of interchangeable gears for determining the pitch of such teeth.

9. In a gear cutting machine the combination of a cutterl head having a slidably mounted plate provided with guides, a cutter carrier mounted Within said guides, a

cutter carried by said cutter carrier, meansV carried Within said head for imparting reciprocatory motion to said-cutter carrier, Work carrying members, one of such memhers being adapted to drive said Work and index such Work, a gear train operatively7 coupling said cutter reciprocating member and said Work indexing means, said gear train having a train of interchangeable gears for determining the'number of teeth to be cut on the Work and havingv a second set of interchangeable gears for determining the pitch of such teeth, and means for compounding the Ysliding motion of said plate with the motion transmitted to said Work indexing means, whereby the cutter and the Work Will register at all times irrespective of the advance of said sliding plate.

10. A gear cutting machine for cutting double helical gears comprising Work carrying' means adapted tol drive and index said Work, a gear train for operating said Work driving means and comprising intermittent motion mechanism for indexing the Work, a

pair of reciprocatory cutters, a pair of cranks for driving' said cutters, gearing connecting said cranks and said gear train for imparting motion to said gear train, a sliding plate carrying said cutters, means for advancing said plate, gearing for compounding the advancing motion of said plate with the indexing motion of said gear train, said gear train having one set 0f gears determining the number of teeth cut in the Work and having a second set ofgears determining thel pitch of such teeth.

ll. A gear cutting machine for cutting double helical gears comprising Work carr ing means adapted to drive and index said Work, al gear train for operating said Work driving vmeans and comprising intermittent motion mechanism for indexing 'the Work, a pair of reciprocatory cutters, a pair of cranks for driving said cutters, gearing connecting said cranks and said gear train for imparting motion to said gear train, a sliding plate carrying said cutters, means for advancing said plate, gearing for compoundlus' lll*

ing the advancing motion of said pluie with ently of the settingof the pitch and the the indexing` motion Said gem' train, said number of teeth. geni' train having one set-'0f gears deterinin- In testimony, that I Aehiiin the rforegoing 10 ing the number of teeth cui', in the Work and l have hereunto set my handv :it Milwaukee, having` a second set of gears determining in the county of Milwaukee and State of the oitch of such teeeh and means 'for vzui'vvisconsin.

`ing the rate 01' feed of saidv plate independl AFRANK XV. JURY., 

